Yeah, that sounds about right, but it's just not working out for me. My times weren't affected before, so I guess I'll have to wait to get to E-Town to see how it fares with the gears and headers.

 

You need to monitor your actual AFR to make sure you are getting the correct fueling first before worrying too much about timing.
Once you know WOT fueling is good (Which will require you to tune your ve table and check your MAF calibration) then you are right to check timing.
You can also run a CAI and Cooler t'stat which will help raise timing a little.
Main problem with too little timing is that most of the combustion pressure is wasted as the piston has past the best point for max break torque in the bore.
Once your timing is set optimal then recheck fueling as changes in timing will affect AFR, so a few itterations of the process will be required.

 

Thanks for the insight, I guess a wideband is in my future, or a trip to the chassis dyno! The car "feels" strong as ever, but everyone knows the
"butt" dyno is not a good tuning tool.

 

My LS6 ran 22 stock and now 28 modified. Did you remember to turn PE back on after you messed with the tune?

 

Yeah, PE is on. I can't figure it out. I'm gonna swap the plugs (unrelated, but due) and look inside the intake for oil on my next swing of days off, next Wed + Thurs.

 

Just a quick update on this old thread. I took the car to East Side Performance and had it dyno'd. Well, 377 RWHP seems pretty good to me. The guys over there were a little surprised at the numbers as well. I think I'll leave well enough alone and not worry about the timing. We left it at 16* and those are the numbers we got.